1. Field of the Invention
The present invention generally relates to a cylinder, and more particularly relates to a locking device for use in a cylinder.
2. Description of Related Art
Cylinders have been used for many years and have been used in combination with clamps or power clamps for many years also. Generally, the cylinder includes a piston, a piston rod and a generally cylindrical body member. The body member has end caps on the end thereof and the body and piston normally include seals and bearings surfaces thereon. The cylinders operate by the input of a fluid or gaseous substance. The most frequently used fluids in the industry are air and oil, however other fluids have been known to be used and other gas substances have also been know to be used to operate a cylinder device. Generally, air cylinders are the preferred device to use in the prior art because of there relatively low cost and reduced maintenance schedule to keep the cylinder and hence clamp operating in the work environment.
The prior art includes many versions of a cylinder that are capable of being opened and closed and locked in various positions. There have been problems in the prior art with the cylinder device locks holding and maintaining a locked position due to the fact that the fluid within the cylinders is apt to leak no matter the design of the check valves and/or seals. Furthermore, pneumatic fluid is capable of losing pressure while in containment and thus reducing mechanical force on the cylinder device to zero and allowing for movement of the piston rod. Therefore, the prior art has difficultly in locking a cylinder device because of heat, high force and long periods of time which eventually lead to devices being released and the pay load dropped or left unsecured because of the pneumatic losses in the cylinder devices.
Many attempts have been made in the prior art to incorporate a cylinder with a braking device. Problems have been encountered in the prior art when the braking device must be released to move the cylinder because the release operation of the braking device generally requires mechanical input from either a second motor or second pneumatic system thus increasing the cost of the cylinder and braking mechanism and making it impractical for many applications. Furthermore, many of the prior art cylinder locking devices are positioned at the top end of the cylinder and allow for the locking of the cylinder when the rod is in its fully extended position. In some prior art mechanisms when the cylinder is in its fully extended position and locked, if a failure of the hydraulic system occurs the rod would be capable of movement. The cylinder could lose its air pressurization lock and allow for unwanted movement of the cylinder and hence movement of the part being held by the cylinder rod. Furthermore, when in the fully retracted position the prior art locking cylinders would not lock the rod in place and hence the rod is capable of movement which could effect the clamping device when the locking cylinder is off or not in use, such as during maintenance. This may result in no fluid pressure being within the locking cylinder device. This could lead to accidents or injuries of workers near the clamps because of the clamp arms falling and parts being dropped because the arm is not in a locked position when in it is fully retracted. Most of the prior art cylinder lock systems also require extra expense because a second hydraulic system is installed to control the locking mechanism and the operation of such locking mechanism. This increases the cost by increasing the number of apertures needed in the end caps and locking cylinder along with the extra parts needed to connect extra hydraulic hoses to the cylinder and the extra room needed to incorporate all these hoses in the extra hydraulic system. Furthermore, the second hydraulic systems as found in the prior art the main component unlocking the cylinder device thus if the second hydraulic system fails the cylinder device is not capable of being unlocked and extensive repairs must be made to unlock the cylinder. Furthermore, many of these prior art cylinder locking devices have complicated systems that require new parts to be made for the end caps and the cylinder as a package and also increases the foot print of the cylinder thus reducing the space available for manufacturing operational needs.
Therefore, there is a need in the art for a new cylinder locking device that is capable of locking the cylinder at both the back end and top end of the cylinder. There is also the need for a cylinder locking device that uses the main piston of the cylinder for the unlocking of the cylinder locking device. This will allow for only the main pneumatic system, used to move the piston, to be used to lock and unlock the cylinder. There is also a need in the art for a cylinder locking device that removes the need for an entire second hydraulic system to operate a cylinder locking device. There is also a need in the art for a low cost dual end locking cylinder device that reduces the complexity of building the cylinder device and the complexity of installing the cylinder locking device in a manufacturing environment. There also is a need in the art for a cylinder device that is capable of being used in a clamping environment and also in a pivot unit environment wherein locking is needed on either one end of a cylinder or both ends of the cylinder.
One object of the present invention is to provide an improved cylinder locking device.
Another object of the present invention is to provide a new cylinder locking device for use in a clamp.
Yet a further object of the present invention is to provide a cylinder locking device capable of being locked at both the top end and back end of a cylinder.
It is yet a further object of the present invention to provide a cylinder locking device that is capable of being used on either end of the cylinder.
It is yet a further object of the present invention to provide a cylinder locking device that uses the main piston of the cylinder as the unlocking mechanism of the locking device.
It is still a further object of the present invention to provide a cylinder locking device that requires only one hydraulic system wherein a second hydraulic system is not needed to operate the locking device for the cylinder rod.
It is a further object of the present invention to provide a cylinder locking device for a clamp wherein only two ports are needed to operate the hydraulic system of the clamp and locking device.
It is still a further object of the present invention to provide a low cost and nearly maintenance free locking device for a cylinder.
To achieve the fore going objects, a cylinder lock for use in the cylinder is disclosed. The cylinder lock includes a rod and a sleeve arranged around the rod. A circular disc having an orifice therethrough with the sleeve arranged within the orifice. The cylinder lock also includes at least one locking member attached to the cylinder disc on one side thereof. The locking member interacts with the rod when the rod is in a locked position.
One advantage of the present invention is that the cylinder locking device includes a locking mechanism at both the top end and back end of the cylinder.
A further advantage of the present invention is that the cylinder locking device uses the main piston of the cylinder for the unlocking of the locking mechanism.
Still another advantage of the present invention is that the cylinder only includes the two main hydraulic ports to operate both the piston and the locking mechanism.
Still a further advantage of the present invention is that only one pneumatic system is needed to operate both the piston and the locking mechanism.
Still another advantage of the present invention is that the cylinder locking device can be used in just one end of the cylinder.
Another advantage of the present invention is that it reduces the cost and external connections for a cylinder locking device in the manufacturing environment.
Still another advantage of the present invention is that the cylinder locking device becomes nearly maintenance free and is also capable of design modifications due to predetermined angles on the cylinder rod and locking member.
Other objects, features and advantages of the present invention will become apparent from the subsequent description and appended claims, taken in conjunction with the accompanying drawings.